Weather Forecast API with FastAPI

Level 3: Real-World

Project Brief

For this project, we will build a RESTful API using FastAPI that simulates a simple weather forecast service. This API will allow users to request a weather forecast for a specified city over a 3-day period. Additionally, users can retrieve the weather forecast for a specific day within this period. The purpose of this project is to introduce you to API development using FastAPI, which is a modern, fast (high-performance) web framework for building APIs with Python 3.6 and above.

Expected Output

1. The user can query 3-day forecast data for different cities:

   For example, visiting http://127.0.0.1:8000/forecast/London will return 3-day forecasts as shown below:

2. The user can also query a certain day in the next 3 days. For example, querying day 2 by visiting http://127.0.0.1:8000/forecast/London/2 would return the following data:

Note that to keep it simple, we are generating fake data. Here is a structure of the code to get you started:

from fastapi import FastAPI
from random import randint, choice

app = FastAPI()

# Sample weather conditions for simulation
weather_conditions = ["Sunny", "Cloudy", "Rainy", "Stormy", "Snowy"]

@app.get("/forecast/{city_name}")
async def get_weather_forecast(city_name: str):
    """Get a 3-day weather forecast for a specific city."""
    ...

    return {"city": city_name, "forecasts": forecast_data}

@app.get("/forecast/{city_name}/{day}")
async def get_specific_day_forecast(city_name: str, day: int):
    """Get the forecast for a specific day in the 3-day range."""
    ...

    return {"city": city_name, "forecast": forecast}

Prerequisites

Required Libraries: fastapi, unicorn
pip install fastapi uvicorn

Required Files: No files are required for this project.

IDE: You can use any IDE on your computer to code the project.

Running the API: To run the API, you need to execute:

uvicorn weather_api:app --reload

where weather_api is the name of your Python script and app is the name of the variable associated to the FastAPI() instance.

Danger Zone

Here is the code solution and the steps to get the app up and running:

Happy Coding!
Daily Python Projects Team